Charge- and/or voltage-controlled micro-electromechanical system (MEMS) devices are often configured in arrays designed to perform a specific task. Examples devices utilizing MEMS arrays include light modulator arrays for displaying images, microphones, speakers, optical scanners, and accelerometers. Generally, each MEMS device of the array is provided with updated control data during each update cycle of the array. For example, data updating schemes for light modulator arrays in projection devices generally involve updating frame data in each MEMS device of the array for every frame of an image being displayed.
One control data updating scheme typically employed when the MEMS array is formed by rows and columns of individual MEMS devices involves writing control data to each of the columns (or rows) of the array and then enabling an update to all MEMS devices in a selected row (or column). This process is repeated sequentially through each row to thereby update each MEMS device of the array for a given update cycle.
Often, however, the control data for a given MEMS device of the array does not change from one update cycle to the next. For arrays that utilize charge-controlled MEMS devices, such as a light modulator array utilizing diffraction-based digital light devices (DLDs) using a variable capacitor to modulate light, each update cycle can require draining a charge based on control data of a prior update cycle from the MEMS device to place the MEMS device in a known charge state before adding an appropriate charge based on control data of a present update cycle. When employing this type of updating scheme, the MEMS device is first discharged and then recharged even when the control data, and thus the charge level, is unchanged from one update cycle to the next. Similarly, voltage-controlled MEMS devices are “re-written” with the same voltage level when the control data is unchanged from one update cycle to the next.
Updating MEMS devices with identical data from one update cycle to the next can cause undue wear on the MEMS devices that can lead to premature device failure, such as a shift in color/intensity of reflected light in a light modulating array. Furthermore, when the MEMS array is a light modulator array for displaying images, such updates can potentially produce unnecessary visual artifacts for a viewer.